Electric welding machine



May 8, 1945. N. REKOSH ELECTRIC WELDING MACHINE Filed Feb. 14, 1944 www'Patented May 8, 1945 ELECTRIC WELDING MACHINE Nate Rekosh, MiamiSprings, Fla., assigner to Consolidated Vultee Aircraft Corporation',San Diego, Calif., a corporation of Delaware Application February 14,1944, Serial No. '522,273

5 Claims.

The invention relates to welding machines.

In welding non-ferrous metals, such as aluminum and magnesium alloys, ahigh pressureis required against the work between the electrodes forwelding. One of the electrodes, usually the upper, is carried by an armwhich is operable to and from an electrode, usually the lower,

which is also carried by an arm. The upper electrode is usuallyshiftable by mechanism, such as a hydraulic ram, and is operated toexert high pressure against the lower electrode. The upper electrode andthe welding tip of 'the lower elec-f One object of the invention is toprovide a` welding machine by which a counter pressure will be exertedon the fixed electrode during the welding periods to minimize relativeangular movement between the electrodes during the application ofwelding current to prevent flashing whichmay burn the work 31j theelectrodes or an inferior weld.

In welding engine cowling for aircraft whichv A is usually provided witha radially curved inturned leading edge it is desirable to provide awelding machine which is adapted to Weld theleading edge, which isusually shaped on a small radius to avoidtlve necessity of riveting thesections of the cowling together, and for this purpose it is desirableto provide upper and lowerv electrodes between which theedge ot thecowling can be welded and which are disposed at one Fig. l is aperspective of a welding'machine embodying the invention. l

Fig. 2 is a front elevation.

Fig. 3 is a vertical section illustrating the manner in which theleading edge of cowling is welded.

The invention is exemplied in a welding machine which eomprises.generally, a main frame or housing a., a hydraulic ram b, suitablysupported from the rear, on the main frame a by a bracket b', and alower support c Whichvhas its rear end fixedly secured on the frame aand carries at its front end a stud c which functions as a holder forthe lower electrode. The support c extends forwardly from the frame aand the stud c is positioned centrally under the ram b. The ramb shiftsthe upper electrode and applies the necessary pressure to the Workbetween the electrodes for welding. The parts thus far described may beof usual construction.

The upper electrode I0 is movable, extends vertically, and is removablyand adjustably secured by a suitable clamp Il in the outer end of an armI2 which functions as a holder for said electrode, connects saidelectrode to the welding circuit, and is movable by the ram. Arm I2extends crosswise of the front of the machine and to one side of theaxis of the ram. The lower end of electrode l0 is provided with awelding tip I6. A channel bar I3 is xedly secured against the under sideof holder-arm I2 by a screw I4 and washer b2. Bar I3 underlaps theholder-arm I2 and is also secured to said arm by a clamping bar 2l andscrews 28. The bar I3 extends away from the ram in a direction oppositefrom the arm I2. The bar I3 extends across the axis of the ram in adirection substantially parallel to the holder-arm l2 and at itsopposite end is reinforced by a plate 30 which is welded to blocks 3|which are welded to the upper face of bar I3. A nut 34 is welded to thebar 30 and a screw-post 33 is threaded to said side of the weldingmachine so that cowling which has a large overall diameter can beconveniently manipulated for welding. Another object of the inventionisto provide an improved machine which is adapted for welding beads onthe leading edge of cowling having a small radius.

Other objects of the invention will appear from the detaileddescription.

The invention consists in the several novel features hereinafter setforth and more particularly defined by claims at the conclusion hereof,

In the drawing:

nut for vertical adjustment of its lower end. A nut 35 is welded to thescrew-post 33 for turning and adjusting said post. A lock nut 36 isadapted t0 secure the post in its adjusted position in the bar 30. Theholder-arm I2 and bar I3 constitute a carrier structure which isoperable by the ram for applying pressure to the work, which extends toopposite sides of the ram on which the structure is supported, and bywhich the electrode I0 and the screw-post 33 are operated vertically onopp0ite sides of the ram. The holder-arm I2 carries the electrode at oneside of the ram and the bar I3 functions as a n member on the oppositeside of the ram for operating the stud 33 to apply a counter pressure tothe lower4 electrode as hereinafter described.

A-lower larm I8 functions as a part o! the lower electrode and isprovided at its outer end with a removable welding tip I9. Arm I8 issecured to the stud c' which functions as an electrode holder for saidarm and through which said arm is connected to the welding circuit.

Arm I8 extends under the holder arm I2 for the upper electrode I and inthe same direction as the arm I2. Arm I8 has its inner end provided witha semi-circular recess fitting against one side of stud c' and isclamped to said stud by an extension arm or member 24 which has anopposite cylindrical seat and bolts 23 which extend through mating lugs25 on the I arm I8 and member 24. Member 24 functions as a rigidextension of the arm I8 at the opposite Vside of the stud c', is alignedcrosswise of the machine with arm I8, and extends under the extensionmember formed by the bar I3 in the upper carrier structure. The outerend of member 24 has ailixed thereto an insulation pad 26 which isengageable by the screw-post 33 which moves with the upper electrode andis shifted by the ram. Arm I8 and member 24 exemplify a structure whichextends crosswise of the machine, extends to the opposite sides of studc', and whereby pressure against the pad 26 on the outer member 24 willexert a counter pressure or balancing pressure on the arm I8 and weldingtip I9 against the work at the welding spot. This counterpressureapplied to arm I8 and welding tip I9 resists relative angular movementbetween the welding tip of the upper and lower electrodes.

Arm I8 is provided with an integral downturned outer end 2I and with anelongated slot 20 extending through the upper and outer corner betweenarm I8 andend 2|. The end 2l has an inward semi-circularly curved lowerportion 2|a which terminates in an upwardly facing seat for a shoulderon the welding tip I9, The portion of the tip I9 below said shoulderfits in a socket 2|b which extends through the inner end of the curvedportion 2la of arm I8. The outer portion of arm I8 is provided with anintegral reinforcing rib I8a which extends around slot 20 and on theupper face off the arm I8. Arm I8 is pro vided between its inner end andthe slot with an integral longitudinal reinforcing rib Ib andextension-member 24 is provided with an integral reinforcing rib 24"L sothat said arm and said extension member will be rigid for thetransmission of pressure stresses. p

The holder-arm I2 for the upper electrode and arm I8 which functions asa holder for the lower electrode tip are preferably formed of a suitablecopper alloy having suitable resistance which will withstand highworking temperature, is resistant to electrolytic and galvanic action,

aavdeae The operation of the machine will be as follows: the work, forexample-the leading edge beading usually with doubler strips forreinforcing or lapping the butt fit between sections oi an en ginecowling d, is inserted over the welding tip I9 into the space betweenthe outer end 2I of arm I8 while ram b and upper electrode I0, arm I2,extension member I3, and screw-post 33 are in their raised position. Thework is spotted on the varm I8 and against the worlr, and a counterpressure to, or balancing Apressure for, that exerted by the upperelectrode against the work, which prevents relative angular movement ofthe faces of the welding tips resulting from angular movement of the armI8 around stud c. The screw-post 33 can be Aadjusted to time theapplication of downward pressure to the extension arm 24 and the upwardpressure of the outer end of arm I8 for work of different thickness.

The welding of the leading edge bead of a small radius on an engineCowling is illustrated in Eig. 3. The hooked form of the outer end ofelectrode arm I8 permits all portions of the bead to be spotted betweenthe electrodes. The electrodes are positioned at one side of the weldingmachine so that the Cowling can be tilted for this purpose. The integralformation of the arrn I8, and its reinforced hook-shaped outer endaround the slot through which the upper electrode passes, provides astrong support for the work and by the use of the downward pressure onthe extension arm it is possible to weld leading edge beads underextremely high pressures.

The invention exemplifies a welding machine in which the welding pointsare supported at the ends of arms, one of which is movable to the other,and means for applying counter or balancing pressure to the lowerelectrode during the and which is adapted to withstand working pres--sures exerted by the hydraulic ram b of as high as 750 to 1100 lbs.without distortionforeiiiciently welding work formed of aluminum orwelding operations. The invention also exemplies a machine provided witha lower electrode arm adapted for welding work having small radialcross-sections, and which is adapted to provide such counter orbalancing pressure on the arm adapted for such work.

The invention is not to be understood as restricted to the details setforth, since these may be modifiedl within the scope of the appendedclaims without departing from the spirit and scope of the invention. y

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent is:

1. An electric Welder comprising a rectilinear-ly slldable structureincluding a ram, an upper arm and an extension member rigid with andextending outwardly in opposite directions from the ram; an electrodecarried by the free end of the upper arm; a stationary support below theram: and a lower electrode-arm and an extension member rigid with andstationarily mounted on said support and extending outwardly from saidsupport in opposite directions, correspondingly to the upper arm and itsextension; the extensions being y provided with rigid labutments fortransmitting positive, counter or balancing pressure from the ram to thelower arm during welding periods.

2. An electric Welder comprising a rectilinearly slidable structure,including a ram, an upper arm and an extension member rigid with andextending outwardly in opposite directions from the ram; an electrodecarried by the free end of the upper arm; a stationary support below theram; and a lower electrode arm and an extension member, rigid with andstationarily mounted on said support and extending outwardly from saidsupport in opposite directions, correspondingly to the upper arm and itsextension; the extensions being provided with rigid abutments fortransmitting positive, counter or balancing pressure from the ram to thelower arm during welding periods, one of said abutments being adjustablefor work of different thickness.

3. An electric Welder comprising a rectilinearly slidable structureincluding a ram, an upper arm and an extension member rigid with andextending outwardly in opposite directions from the ram; an electrodecarried by the free end of the upper arm; a stationary support below theram; and a lower electrode arm and an extension member rigid with andstationarily mounted on saidA support and extending outwardly from saidsupport in opposite directions correspondingly to the upper arm and itsextension; one of the extensions being provided with a rigid abutment,andthe other with an adjustable screw for transmitting positive, counteror balancing pressure` from the ram to the lower arm during weldingperiods.

4. An electric welder comprising a supporting frame; a ram supportedbythe frame for rectilinear sliding movement; an upper arm and anextension member, rigid and rectilinearly movable with and extendingoutwardly from the opposite sides of the ram; an electrode carried bysaid upper arm, a supporting stud rigidly supported on andprojectingfrom the frame ybelow the center of the ram; and a lowerelectrode arm' and an extension-member rigidly secured thereto,stationarily mounted on and extending outwardly from opposite sides ofthe stud and correspondingly to the upper arm and extension-member; saidextension members being provided with abutments for transmittingpositive counter or` balancing pressure from the ram to the lowerelectrede-arm during the welding periods.

5. An electric Welder comprising a supporting frame; a ram supported bythe frame for rectilinearsliding movement; an upper arm and anextension-member, rigid, rectilinearly movable with and extendingoutwardly from the opposite sides of the ram; an electrode carried bysaid upper arm; a supporting stud rigidly supported on and projectingfrom the frame below the center of the ram; a lower electrode arm and anextension-member rigidly secured thereto, extending outwardly fromopposite sides of the stud and under the upper arm and extension member;and

NA''E REKosH.'

